Registration Dossier

Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

NOEC (14 d) ≥ 1000 mg/kg dw for Eisenia fetida (OECD 207)

Key value for chemical safety assessment

Additional information

No experimental data evaluating the toxicity of Glycerides, C12-18 di- and tri- (CAS No. 91744-28-4) to soil macroorganisms are available.

Therefore, earthworm toxicity studies conducted on two other Glyceride category members (propane-1,2,3-triyl trisheptanoate (CAS No. 620-67-7) and Glycerides, C14-18 and C16-18 unsatd. mono-, di- and tri- (CAS No. 91052-28-7) are used as read across (in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5). Both read-across substances and the target substance are fatty acid esters of glycerol. All three substances exhibit log Kow/Pow values > 3, indicating high adsorption potential to soil particles. Tests with soil-dwelling organisms that feed on soil particles are therefore most relevant for the evaluation of their soil toxicity. In the absence of a clear indication of selective toxicity, an invertebrate (earthworm or collembolan) test is preferred, as outlined in Guidance on information requirements and chemical safety assessment Chapter R.7.c (ECHA, 2012).  Propane-1,2,3-triyl trisheptanoate (CAS No. 620-67-7) and Glycerides, C14-18 and C16-18 unsatd, mono-, di- and tri- (CAS No. 91052-28-7) cover the whole fatty acid C-chain range within the Glycerides category and also different degrees of esterification. Therefore, these two substances are expected to be good representatives of the toxicity of Glycerides to soil macroorganisms, including Glycerides, C12-C18, di- and tri- . For all three substances, toxicity to aquatic organisms is low, if any. Propane-1,2,3-triyl trisheptanoate (CAS No. 620-67-7) did not show toxicity to aquatic organisms up to the limit of its water solubility. Glycerides, C14-18 and C16-18 unsatd. mono-, di- and tri- (CAS No. 91052-28-7) showed no toxicity to fish and aquatic invertebrates up to the limit of their water solubility. Effects on algal growth rate were observed this substance, leading to a NOELR value of 32 mg/L (loading rate). Since these effects occurred well above the water solubility of the substance, the possibility of physical effects (due to disturbance of algae cells by emulsified test substance) instead of, or in addition to toxicological effects, cannot be excluded. The acute toxicity test available for Glycerides, C12-18 di- and tri- (read-across data) on fish showed no adverse effects occurred in the range of the water solubility of the substance (4-7 mg/L). Effects were observed in the tests conducted with aquatic invertebrates and algae (read-across data). However, the WAFs in these two tests, in which effects were observed later on, were reported to be turbid. Therefore,physical effects due to interference with emulsified test substance with daphnids and algae cannot be excluded. Based on their structural similarity and comparable aquatic toxicity profile, it is justified to use the available read-across substances to cover this endpoint.

 

Both tests were performed according to OECD 207, under GLP conditions (Muckle, 2012; Moser, 2012). In both studies, the test organism Eisenia fetida was exposed to the test substance for 14 days at a concentration of 1000 mg/kg dw (limit test). No effects on survival or biomass were reported during the exposure period, leading to NOEC values (14 d) ≥ 1000 mg/kg dw.

 

Glycerides, C12-C18, di- and tri- is readily biodegradable. Therefore, rapid and ultimate degradation in the environment, including soil, can be expected. Chronic exposure of terrestrial organisms is thus very unlikely. Due to the metabolization via enzymatic hydrolysis of the Glycerides category members, a relevant uptake and bioaccumulation in biota is not expected. Enzymatic breakdown will initially lead to the free fatty acid and glycerol. Glycerides are naturally stored by organisms as long-term energy reserves. Especially in periods in which the energy demand is high (reproduction, migration, etc.), glycerides are mobilized from the storage sites as source of fatty acids. Fatty acid catabolism is the most important energy source in many species, resulting in the release of acetyl CoA and NADH (throughβ-oxidation) and eventually, via the tricarboxylic cycle, the production of metabolic energy in the form of ATP. Please refer to IUCLID Section 5.3.1 for a detailed overview on bioaccumulation of the Glycerides category members.

Based on the results obtained for the two similar category members (in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5) and the characteristics of Glycerides, C12-18 di- and tri- (CAS No. 91744-28-4), this substance is not expected to show toxicity to soil macroorganisms